I don't blame people for being on the fence about buying the game when it is still primarily a block-based building game. The way I see it is that I paid 10 bucks for it, and I have probably played for about 40+ hours so far. 10 bucks is about as much as I would pay to go see a movie. Since I have already spent 40 hours on an alpha build of a game, I stand to gain even more value once the game gets all of the other cool crap that Notch has said he wants to do.
The development has sort of slowed down as of recently, but I'm hoping that after he gets situated at the new office and he fixes the server so he can handle the exponential rate at which he is selling this game he will have time to make some more cool shit. That is hoping he doesn't start dicking around more that he is rich. He tweeted that the office has a HOT TUB in it.